Plasma microRNA-192-5p can predict the response to neoadjuvant chemotherapy and prognosis in esophageal cancer.

Esophageal cancer (EC) is the sixth leading cause of cancer-related death worldwide. Recently, neoadjuvant chemotherapy (NAC) before curative surgery has become a standard treatment for clinical stage II or III EC patients. Some EC patients receive complete response (CR) by NAC; thus, curative surgery may be unnecessary for such patients. MicroRNA level in plasma has potential as a predictor of response to NAC. In the present study, we focused on miR-192-5p, which is highly expressed in EC tissue. The purpose was to investigate correlations between levels of plasma miR-192-5p and response to NAC. Furthermore, molecular functions of miR-192-5p associated with chemo-sensitivity were examined using EC cell lines. Level of miR-192-5p in plasma before surgery was evaluated in 113 EC patients. Sixty-nine patients received NAC. miR-192-5p levels in the CR group were significantly higher than the other groups (p = 0.002). Downregulation of miR-192-5p in EC cell line inhibited sensitivity to cisplatin, and overexpression of miR-192-5p in EC cell line promoted sensitivity to cisplatin. miR-192-5p regulated the sensitivity to cisplatin by targeting ERCC3 and ERCC4. Plasma miR-192-5p may be used as a predictor of response to chemotherapy and prognosis in EC patients.